Method for upgrading coal gasification products

ABSTRACT

A method for upgrading gasification products produced by the gasification of subterranean carbonaceous deposits and recovered through a well bore by contacting said products with an effective amount of a suitable catalyst positioned in said well bore.

United States-Patent 1191 Parsons et a1.

[ 1 July 16, 1974 METHOD FOR UPGRADING COAL GASIFICATION PRODUCTS Inventors: Roger C. Parsons; Kang Yang,

Ponca City, both of Okla.

Assignee: Continental Oil Company, Ponca City, Okla.

Filed: Apr. 30, 1973 Appl. No.: 355,854

US. Cl. 166/260, 166/302 Int. Cl E211) 43/24 Field of Search 48/197 R, DIG. 6; 208/10,

References Cited UNITED STATES PATENTS 8/1962 Reichle 166/260 X 3,072,187 1/1963 Carr 208/9 X 3,087,540 4/1963 Parker 166/260 3,095,925 7/1963 Marx 166/260 3,127,935 4/1964 Poettmann et a1 166/260 3,595,316 7/1971 Myrick 166/303 Primary Examiner-David H. Brown Attorney, Agent, or Firm-1 Lindsey Scott [57] ABSTRACT A method for upgrading gasification products produced by the gasification of subterranean carbonaceous deposits and recovered through a well bore by contacting said products with an effective amount of a suitable catalyst positioned in said well bore.

10 Claims, 1 Drawing Figure 1 METHOD FOR UPGRADING COAL GASIFICATION PRODUCTS FIELD OF THE INVENTION This invention relates to the gasification of subterranean carbonaceous deposits. This invention is further related to catalytically converting the gasification prod ucts produced by the gasification of subterranean carbonaceous deposits into more desirable products. This invention further relates to contacting the gasification products with a catalyst to increase the hydrocarbon content of the gasification products. This invention further relates to contacting gasification products with a catalyst to increase the hydrogen content of the gasification products.

BRIEF DESCRIPTION OF THE PRIOR ART Numerous 'methods are known to the art for the gasification of subterranean carbonaceous deposits. In one method, a well is drilled into the carbonaceous deposits and a pipe is positioned centrally in the well bore. The gasification gas is injected through the pipe into the carbonaceous deposit, the carbonaceous deposit is gasified, and the gasification products are recovered between the inner diameter of the well bore and the outer diameter of the pipe. In another method, air is injected into a first well bore, combustion is initiated in the carbonaceous deposit,-and the gasification products are recovered from a second well bore. The gasification products typically comprise a mixture of carbon dioxide, carbon monoxide, nitrogen, hydrogen, light hydrocarbons, and the like. Such gases typically contain from about to 30 percent of the gas as carbon monoxide and hydrogen. Such gases typically have a heating value of about 100 BTUs per cubic foot. It is desirable that the product gashave a higher heating value.

Numerous methods are known for increasing the BTU value of the gas. One such process is the Lurgi process. The main disadvantage of such processes is that the plants are quite expensive. For example, a plant for converting 250 million cubic feet per day of gas by the Lurgi process could be expected to cost in the neighborhood of $220 million. The desirability of the gasification products as heating materials, raw materials for chemical processes, and the like is determined primarily by their availability and low cost. It is obvious that such expensive facilities for processing the product gases increases the cost dramatically. As a result of the present shortage of available hydrocarbon fuels and the like, it is desirable that a process be available whereby the value of the gasification products for commercial use in heating, as chemical raw materials and the like, can be increased.

OBJECT OF THE INVENTION An object of the present invention is to provide a method whereby the gasification products produced by the gasification of subterranean carbonaceous deposits can be upgraded. It is a further objective of the present invention to provide a method for catalytically upgrading gasification products. It is a further objective of the present invention to increase the hydrocarbon content of the gasification products from the gasification of subterranean carbonaceous deposits by contacting such products with a catalyst. It is a further objective of the present invention to provide a method whereby the hydrogen content of gasification products produced by the gasification of subterranean carbonaceous deposits may be increased by contacting said products with a catalyst.

SUMMARY OF THE INVENTION It has now been found that the objectives of the present invention are achieved in a method for upgrading gasification products produced by the gasification of subterranean carbonaceous deposits and recovered through a wellbore by contacting saidproducts with an effective amount of a suitable catalyst positioned in the well bore.

DESCRIPTION OF THE DRAWING The drawing shows a typical embodiment of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS In the embodiment of the present invention shown in the FIGURE, a coal deposit, 10, is shown covered by an overburden, 11, wherein the coal deposit is penetrated by a well bore, 13, which connects the coal deposit with the surface, 12. A pipe, 14, is positioned inside the well bore so' that air flow as shown by the arrows, 15, into the carbonaceous deposit is as shown. Combustion is initiated in the coal deposit in a combustion cavity, 16, at combustion surfaces, 18. The product'gas flow is as shown by the arrows, 19. The catalyst, 20, is positioned as shown onthe exterior of the pipe so that the product gas as produced flows over and aboutthe catalyst, thereby upgrading the product gas in the production well.

As will be obvious to those skilled in the art, many variations and modifications of the present invention are possible. The illustration shown in the figure is illustrative and should not be considered limiting since processes wherein the injection gas is injected via a first well bore and the product gas is produced through a second well bore as well as other embodiments known to those skilled in the art are within the scope of the present invention. In particular, the catalyst may be positioned on the inside of a well bore, on the inside or outside-of a pipe diameter, or at other convenient positions in the well bore so that the product gas in its flow from the carbonaceous deposit to the surface is contacted by the catalyst.

Suitable carbonaceous deposits are deposits such as coal, peat, shale oils, heavy petroliferous deposits, and the like.

The gasification products typically contain carbon dioxide, carbon monoxide, nitrogen, hydrocarbons, and hydrogen. The products may also contain steam when steam is used as an injection gas, and it is observed that often carbon monoxide and hydrogen constitute from 20 to 30 percent of the gaseous product. As noted hereinbefore the BTU value of such products is typically in the neighborhood of BTU s per cubic foot. It is highly desirable that the BTU value be raised, and it has been found that by the process of the present invention, BTU values of approximately 250 BTUs per cubic foot are possible.

In one embodiment of the present invention, a material such as Fe O NiO, and FeSO is used as the catalyst to upgrade the product gas by increasing the hydrocarbon content of the gas. In particular, contacting the product gaswith a catalyst as described as been found to increase the hydrocarbon content significantly when a pressure of from about 50 to about 500 psi was used in conjunction with a temperature from about 100C to about 500C. Desirable results have been obtained wherein the temperature is from about 300C to about 400C and the pressure is from about 100 to about 200 psi. Very desirable results have been obtained when Fe O was used as the catalyst.

In a further embodiment of the present invention, it has been found that when the product gas is contacted with a catalyst such as Fe O or F c80 at a temperature from about 100C to about 500C and a pressure from about atmospheric to about 100 psi, the hydrogen content of the product gas is increased. Desirable results have been achieved wherein the catalyst used in Fe O Very desirable results have been obtained wherein the temperature is from about 300C to about 400C and the pressure is atmospheric.

The catalyst must be present in an effective amount. An effective amount is expected to vary widely depending upon the particular configuration of the bore hole, the length of the well bore, and the like. It is believed that an effective amount of the catalyst will be obvious to those skilled in the art in light of the particular parameters associated with the particular gasification operation in conjunction with which present invention is used.

The catalyst may be positioned in the well bore by any convenient method. For example, the well bore interior may be impregnated with the catalyst, the piping may be coated internally or externally with the catalyst, aqueous solutions of the catalyst may be introduced continuously or intermittently into the well bore and the like. Such modifications and variations are well known to those skilled in the art and need not be discussed further.

While applicants do not wish to be bound by any particular theory, it is believed that the production of hydrocarbon products in the gasification product gas is illustrated by the following reaction.

atures and pressures in the presence of a catalyst (theoretical).

P(atm) W 300 400 500 600 700 800 mole percent ethylene The chemistry involved in the foregoing reactions is well known to thoseskilled in the art, and the primary point of novelty in applicants claimed invention lies in the fact that applicant has discovered a new and economical method by which gasification products may be upgraded to highly desirable products at a minimal cost. In the conversion of the product gas to product gas higher in hydrogen, the chemistry is typified by the following reactions.

Fe H O FeO+ H FeO CO CO Fe Catalyst C0 H O CO H2 It is thus illustrated that the product gases may be increased in hydrogen content. As noted hereinbefore, the reactions shown are well known to those skilled in the art, and the primary novelty in the present application lies in positioning the catalyst in the well bore and thus using the well bore as a reactor for-upgrading the product gases. I

It will be noted that the gases produced can be further upgraded (on the surface) by processes such as those typified by the following reactions;

Ca(OI-I) CO CaCo H CaCO H 0 Ca(OI-I) co The reactions (e) and (f) are well known to those skilled in the art and are merely pointed out as useful to those skilled in the art in conjunction with the practice of the present invention. 1

As is obvious to those skilled in the art, the gases produced by the practice of applicants claimed invention may be used in a variety of ways. Upon producing the 'gas, the hydrogen or the hydrocarbon portion may be recovered and sold as such, leaving a gas which still has an increased BTU value, or the upgraded gases may be sold as such for use as heating gases and the like. Other uses, such as chemical feed streams and the like, are wellknown to those skilled in the art and need not be discussed further.

Having thus described the invention, it is pointed out that the embodiments described hereinbefore are illustrative in nature and are not to be construed as limitations. In fact, many variations and modifications are possible within the scope of the present invention, and it is believed that such modifications and variations may appear obvious or desirable to those skilled in the art upon a review of the foregoing description of preferred embodiments.

EXAMPLE In situ gasification was simulated in thelaboratory by using a fixed bed reactor placed in a furnace. Water or water containing a catalyst, F e was introduced into the outlet of the reactor. In the tests 40 g of one-fourth Table I TIME VOL H (Min) Test l Test II 50 2l.9 31.5 70 7.4 10.3 90 6.8 9.7 110 3.3 9.3 I30 2.7 83 I50 2.1 7.2 170 1.6 8.l

The tests shown clearly illustrate that the gasification product gases are upgraded by contacting with FeSO as a catalyst in the reactor outlet.

Heretofore many processes have positioned a catalyst in the reaction zone to upgrade gasification products and the like, but it has not been known heretofore that the recovery well and the like could be used to eatalytically upgrade the reaction products. As shown above significant improvements are achieved by such a catalytic contacting. In fact one use for applicants process is in the further upgrading of gasification products produced in'reactions wherein catalysts are used in the reaction zone and the like.

Having thus described the invention we claim:

1. A method for upgrading gasification products produced by the gasification of subterranean carbonaceous deposits and recovered through a well bore by consisting of Fe O and FeSO I 6 contacting said products with an effective amount of a suitable catalyst positioned in said well bore.

2. The method of claim 1 wherein said gasification products comprise mixtures of carbon dioxide, carbon monoxide, nitrogen, hydrocarbon, and hydrogen, and wherein said carbonaceous deposits are coal or shale deposits.

3. The method of claim 2 wherein said mixtures are upgraded to contain increased quantities of hydrocarbons and wherein said catalyst is selected from the group consisting of Fe O MO, and FeSO.,.

4. The method of claim 3 wherein said hydrocarbons are selected from the group consisting of methane, ethane, propane, and ethylene.

5. The method of claim 3 wherein said catalyst is Fe O or FeSO...

6. The method of claim 2 wherein said products are contacted with said catalyst at a temperature from about C to about 500C and a pressure from about 50 to about 500 psi.

7. The method of claim 6 wherein said temperature is from about 300C to about 400C and wherein said pressure is from about 100 to about 200 psi.

8. The method of claim 2 wherein said mixtures are upgraded to contain increased quantities of hydrogen and wherein said catalyst is selected from the group 9. The method of claim 8 wherein said products are contacted with said catalyst at temperature from about 100C to about 500C and a pressure from about atmospheric to about 100 psi.

10. The method of clairn 9 wherein said temperature is from about 300C to about 400C. 

2. The method of claim 1 wherein said gasification products comprise mixtures of carbon dioxide, carbon monoxide, nitrogen, hydrocarbon, and hydrogen, and wherein said carbonaceous deposits are coal or shale deposits.
 3. The method of claim 2 wherein said mixtures are upgraded to contain increased quantities of hydrocarbons and wherein said catalyst is selected from the group consisting of Fe2O3, NiO, and FeSO4.
 4. The method of claim 3 wherein said hydrocarbons are selected from the group consisting of methane, ethane, propane, and ethylene.
 5. The method of claim 3 wherein said catalyst is Fe2O3 or FeSO4.
 6. The method of claim 2 wherein said products are contacted with said catalyst at a temperature from about 100*C to about 500*C and a pressure from about 50 to about 500 psi.
 7. The method of claim 6 wherein said temperature Is from about 300*C to about 400*C and wherein said pressure is from about 100 to about 200 psi.
 8. The method of claim 2 wherein said mixtures are upgraded to contain increased quantities of hydrogen and wherein said catalyst is selected from the group consisting of Fe2O3 and FeSO4.
 9. The method of claim 8 wherein said products are contacted with said catalyst at temperature from about 100*C to about 500*C and a pressure from about atmospheric to about 100 psi.
 10. The method of claim 9 wherein said temperature is from about 300*C to about 400*C. 